Tubular apparatus is commonplace in fluid handling systems, e.g. tanks for storage, piping for transport, and pumps for fluid pressurization. Typically, the tubular apparatus is subject to wear primarily as a function of the chemical composition, temperature and abrasiveness of the fluid being handled. Severe use situations are found where two or more of the mentioned wear contributing factors are found together. In coal slurry handling, for example, and concrete pumping, chemically aggressive compositions are all the more difficult to handle because the myriad small particles which make up these slurries attack the tubular apparatus by a process referred to as erosion, the gradual wearing away of the surface of the tubular apparatus by continual bombardment with fine particulates, the process usually behing enhanced by the chemical nature of the slurry composition. In severe usage situations, the wear is caused not so much by large particle abrasion as by millions of minute contacts by the small particles which characterize fine particulate slurries.
Typically, the tubular apparatus is fabricated of steel, generally a carbon steel, and sometimes an iron base stainless steel. Such tubular apparatus can be improved in erosion wear resistance in accordance with the invention.
Importantly, the erosion resistance benefits conferred by the invention can be obtained locally in areas needing them, so that the entire fluid handling system need not be fabricated of exotic materials, nor coated entirely with a specialized coating which in fact is needed only here and there.